kernel/drivers/net/can/sja1000/sja1000_platform.c

   1 /*
   2  * Copyright (C) 2005 Sascha Hauer, Pengutronix
   3  * Copyright (C) 2007 Wolfgang Grandegger <wg@grandegger.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the version 2 of the GNU General Public License
   7  * as published by the Free Software Foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/netdevice.h>
  22 #include <linux/delay.h>
  23 #include <linux/pci.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/irq.h>
  26 #include <linux/can/dev.h>
  27 #include <linux/can/platform/sja1000.h>
  28 #include <linux/io.h>
  29 #include <linux/of.h>
  30 #include <linux/of_irq.h>
  31
  32 #include "sja1000.h"
  33
  34 #define DRV_NAME "sja1000_platform"
  35 #define SP_CAN_CLOCK  (16000000 / 2)
  36
  37 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
  38 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
  39 MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the platform bus");
  40 MODULE_ALIAS("platform:" DRV_NAME);
  41 MODULE_LICENSE("GPL v2");
  42
  43 static u8 sp_read_reg8(const struct sja1000_priv *priv, int reg)
  44 {
  45         return ioread8(priv->reg_base + reg);
  46 }
  47
  48 static void sp_write_reg8(const struct sja1000_priv *priv, int reg, u8 val)
  49 {
  50         iowrite8(val, priv->reg_base + reg);
  51 }
  52
  53 static u8 sp_read_reg16(const struct sja1000_priv *priv, int reg)
  54 {
  55         return ioread8(priv->reg_base + reg * 2);
  56 }
  57
  58 static void sp_write_reg16(const struct sja1000_priv *priv, int reg, u8 val)
  59 {
  60         iowrite8(val, priv->reg_base + reg * 2);
  61 }
  62
  63 static u8 sp_read_reg32(const struct sja1000_priv *priv, int reg)
  64 {
  65         return ioread8(priv->reg_base + reg * 4);
  66 }
  67
  68 static void sp_write_reg32(const struct sja1000_priv *priv, int reg, u8 val)
  69 {
  70         iowrite8(val, priv->reg_base + reg * 4);
  71 }
  72
  73 static void sp_populate(struct sja1000_priv *priv,
  74                         struct sja1000_platform_data *pdata,
  75                         unsigned long resource_mem_flags)
  76 {
  77         /* The CAN clock frequency is half the oscillator clock frequency */
  78         priv->can.clock.freq = pdata->osc_freq / 2;
  79         priv->ocr = pdata->ocr;
  80         priv->cdr = pdata->cdr;
  81
  82         switch (resource_mem_flags & IORESOURCE_MEM_TYPE_MASK) {
  83         case IORESOURCE_MEM_32BIT:
  84                 priv->read_reg = sp_read_reg32;
  85                 priv->write_reg = sp_write_reg32;
  86                 break;
  87         case IORESOURCE_MEM_16BIT:
  88                 priv->read_reg = sp_read_reg16;
  89                 priv->write_reg = sp_write_reg16;
  90                 break;
  91         case IORESOURCE_MEM_8BIT:
  92         default:
  93                 priv->read_reg = sp_read_reg8;
  94                 priv->write_reg = sp_write_reg8;
  95                 break;
  96         }
  97 }
  98
  99 static void sp_populate_of(struct sja1000_priv *priv, struct device_node *of)
 100 {
 101         int err;
 102         u32 prop;
 103
 104         err = of_property_read_u32(of, "reg-io-width", &prop);
 105         if (err)
 106                 prop = 1; /* 8 bit is default */
 107
 108         switch (prop) {
 109         case 4:
 110                 priv->read_reg = sp_read_reg32;
 111                 priv->write_reg = sp_write_reg32;
 112                 break;
 113         case 2:
 114                 priv->read_reg = sp_read_reg16;
 115                 priv->write_reg = sp_write_reg16;
 116                 break;
 117         case 1: /* fallthrough */
 118         default:
 119                 priv->read_reg = sp_read_reg8;
 120                 priv->write_reg = sp_write_reg8;
 121         }
 122
 123         err = of_property_read_u32(of, "nxp,external-clock-frequency", &prop);
 124         if (!err)
 125                 priv->can.clock.freq = prop / 2;
 126         else
 127                 priv->can.clock.freq = SP_CAN_CLOCK; /* default */
 128
 129         err = of_property_read_u32(of, "nxp,tx-output-mode", &prop);
 130         if (!err)
 131                 priv->ocr |= prop & OCR_MODE_MASK;
 132         else
 133                 priv->ocr |= OCR_MODE_NORMAL; /* default */
 134
 135         err = of_property_read_u32(of, "nxp,tx-output-config", &prop);
 136         if (!err)
 137                 priv->ocr |= (prop << OCR_TX_SHIFT) & OCR_TX_MASK;
 138         else
 139                 priv->ocr |= OCR_TX0_PULLDOWN; /* default */
 140
 141         err = of_property_read_u32(of, "nxp,clock-out-frequency", &prop);
 142         if (!err && prop) {
 143                 u32 divider = priv->can.clock.freq * 2 / prop;
 144
 145                 if (divider > 1)
 146                         priv->cdr |= divider / 2 - 1;
 147                 else
 148                         priv->cdr |= CDR_CLKOUT_MASK;
 149         } else {
 150                 priv->cdr |= CDR_CLK_OFF; /* default */
 151         }
 152
 153         if (!of_property_read_bool(of, "nxp,no-comparator-bypass"))
 154                 priv->cdr |= CDR_CBP; /* default */
 155 }
 156
 157 static int sp_probe(struct platform_device *pdev)
 158 {
 159         int err, irq = 0;
 160         void __iomem *addr;
 161         struct net_device *dev;
 162         struct sja1000_priv *priv;
 163         struct resource *res_mem, *res_irq = NULL;
 164         struct sja1000_platform_data *pdata;
 165         struct device_node *of = pdev->dev.of_node;
 166
 167         pdata = dev_get_platdata(&pdev->dev);
 168         if (!pdata && !of) {
 169                 dev_err(&pdev->dev, "No platform data provided!\n");
 170                 return -ENODEV;
 171         }
 172
 173         res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 174         if (!res_mem)
 175                 return -ENODEV;
 176
 177         if (!devm_request_mem_region(&pdev->dev, res_mem->start,
 178                                      resource_size(res_mem), DRV_NAME))
 179                 return -EBUSY;
 180
 181         addr = devm_ioremap_nocache(&pdev->dev, res_mem->start,
 182                                     resource_size(res_mem));
 183         if (!addr)
 184                 return -ENOMEM;
 185
 186         if (of)
 187                 irq = irq_of_parse_and_map(of, 0);
 188         else
 189                 res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 190
 191         if (!irq && !res_irq)
 192                 return -ENODEV;
 193
 194         dev = alloc_sja1000dev(0);
 195         if (!dev)
 196                 return -ENOMEM;
 197         priv = netdev_priv(dev);
 198
 199         if (res_irq) {
 200                 irq = res_irq->start;
 201                 priv->irq_flags = res_irq->flags & IRQF_TRIGGER_MASK;
 202                 if (res_irq->flags & IORESOURCE_IRQ_SHAREABLE)
 203                         priv->irq_flags |= IRQF_SHARED;
 204         } else {
 205                 priv->irq_flags = IRQF_SHARED;
 206         }
 207
 208         dev->irq = irq;
 209         priv->reg_base = addr;
 210
 211         if (of)
 212                 sp_populate_of(priv, of);
 213         else
 214                 sp_populate(priv, pdata, res_mem->flags);
 215
 216         platform_set_drvdata(pdev, dev);
 217         SET_NETDEV_DEV(dev, &pdev->dev);
 218
 219         err = register_sja1000dev(dev);
 220         if (err) {
 221                 dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
 222                         DRV_NAME, err);
 223                 goto exit_free;
 224         }
 225
 226         dev_info(&pdev->dev, "%s device registered (reg_base=%p, irq=%d)\n",
 227                  DRV_NAME, priv->reg_base, dev->irq);
 228         return 0;
 229
 230  exit_free:
 231         free_sja1000dev(dev);
 232         return err;
 233 }
 234
 235 static int sp_remove(struct platform_device *pdev)
 236 {
 237         struct net_device *dev = platform_get_drvdata(pdev);
 238
 239         unregister_sja1000dev(dev);
 240         free_sja1000dev(dev);
 241
 242         return 0;
 243 }
 244
 245 static const struct of_device_id sp_of_table[] = {
 246         {.compatible = "nxp,sja1000"},
 247         {},
 248 };
 249 MODULE_DEVICE_TABLE(of, sp_of_table);
 250
 251 static struct platform_driver sp_driver = {
 252         .probe = sp_probe,
 253         .remove = sp_remove,
 254         .driver = {
 255                 .name = DRV_NAME,
 256                 .of_match_table = sp_of_table,
 257         },
 258 };
 259
 260 module_platform_driver(sp_driver);